1. Field of the Invention
The present invention relates to a method for producing and to a welded pipe connection.
2. Brief Description of the Background of the Invention Including Prior Art
In addition to butt welding connections also socket type welding connections with straight or ball type sockets are employed in steel pipe line construction. Such connections are specified for example in German Industrial Standard DIN 2461. These welded socket connections have as a connecting seam a circumferential fillet welding seam welded from the outside of the pipes.
Steel pipes with such connections can be easily, rapidly and simple laid and welded. Upon employing of welding ball sockets expensive bending of the pipes at the construction site can be avoided. In case of pipes with diameters larger than 2 meters the present day bending apparatus are not capable of providing such a bent pipe.
In the laying of pipe into the ground and in particular with socket pipes of a larger diameter, the outer welding seam between female socket and male end is performed in the trench for the pipe. This requires the digging of the so-called head holes in order to provide sufficient work area for the welding operation. These holes have to be particularly large in cases where the welding seam is to be provided by an automatic welder. For example in case of pipes having a diameter of three meter thus head holes result having a cross-section of more than 20 meters squared. This is an unbearably high expense, which has to be repeated every 6 to 25 meters of length of pipe depending on the lengths of the pipes employed.
In addition, centering devices are known which aid in butt welding of pipes to a pipe line on construction sites as is taught for example in U.S. Pat. No. 3,979,041.